The Novoflex C-Mount to BALPRO1 or BALPRO T/S Bellows Adapter allows you to use a C-mount lens upon the Novoflex BALPRO1 or BALPRO T/S bellows systems.
The BALPRO bellows are larger bellows which also accept medium-format cameras and lenses in addition to 35mm system cameras and lenses. As the hole on the BALPRO is large enough to accept a medium format lens, when you're using it with a 35mm system lens you must first reduce the front of the device to the Leica screw mount standard by installing the Novoflex PROLEI adapter. From that PROLEI, with its incumbent female Leica screw mount threading, Novoflex makes a host of adapters to use other lenses-such as this LEICE adapter, which allows you to install a C-mount lens.
The fact that you're using a C-mount lens doesn't have anything to do with the rear of the bellows; you could use any 35mm system you liked, and even perhaps a medium format system if the bellows was extended far enough so that the C-mount lens' field of view began to fully cover the medium format image area.
